VB -> C#: Exit Do/For/While/Select treated as `break` even when within another breakable block

[marcal]

Hello (and best wishes),

I have seen an error where the converted code doesn't give the expected result.

Input code

Public Class VisualBasicClass
	Public sub Test
		dim LstTmp as new List (of Integer)
		LstTmp.Add (5)
		LstTmp.Add (6)
		LstTmp.Add (7)
		LstTmp.Add (8)
		LstTmp.Add (9)
		LstTmp.Add (10)
		dim i_Total as integer 
		for each CurVal as integer in LstTmp
			i_Total +=CurVal
			Select case CurVal
			Case 6
				Exit For 
			End select 
		Next
		Messagebox.show (i_Total.Tostring())
	End Sub
End Class

Erroneous output

public void Test()
    {
        var LstTmp = new List<int>();
        LstTmp.Add(5);
        LstTmp.Add(6);
        LstTmp.Add(7);
        LstTmp.Add(8);
        LstTmp.Add(9);
        LstTmp.Add(10);
        var i_Total = default(int);
        foreach (int CurVal in LstTmp)
        {
            i_Total += CurVal;
            switch (CurVal)
            {
                case 6:
                    {
                        break;
                    }
            }
        }

        MessageBox.Show(i_Total.ToString());
    }

Expected output

public void Test()
    {
        var LstTmp = new List<int>();
        LstTmp.Add(5);
        LstTmp.Add(6);
        LstTmp.Add(7);
        LstTmp.Add(8);
        LstTmp.Add(9);
        LstTmp.Add(10);
        var i_Total = default(int);
        foreach (int CurVal in LstTmp)
        {
           bool bo_ExitFor = false;
            i_Total += CurVal;
            switch (CurVal)
            {
                case 6:
                    {
                    bo_ExitFor = true;
                        break;
                    }
            }
            if (bo_ExitFor) break;
        }

        MessageBox.Show(i_Total.ToString());
    }

Details

• Product in use: VS extension
• Version in use: e.g. 8.2.1
• It didn't work before
• It is also possible to do a function with a return Value of true to trigger the Break
  It should at least give an error because the code doesn't work like before (VB ==> 11 and C#==>45).
  It is also possible to convert to if (.....) but you lose some visibility.

[GrahamTheCoder]

Thanks for the report and good suggestion on a fix. There will be a few variants with other nested structures too since VB has more specific exit keywords: https://github.com/icsharpcode/CodeConverter/blob/master/CodeConverter/CSharp/MethodBodyExecutableStatementVisitor.cs#L410-L437
One other solution that is much less idiomatic c#, but probably easier to implement would be adding a label at the end of each structure and use "go to".
Hopefully we can implement as you suggested though.

[GrahamTheCoder]

In df6354b I turned this into a compilation error so that it at least can't surprise anyone